Device for testing electric circuits



Oct. 23, 1923. 1,471,432

G. W. WEIFORD, JR

DEVICE FOR TESTING ELECTRIC CIRCUITS Filed Nov. 12 1921 2 Sheets-$heet 1gwvemtcw GEORGE W. WE/FORD, JR,

Oct. 23 1923. 1,471,432

G. W. WEIFORD. JR

DEVICE FOR TESTING ELECTRIC CIRCUITS Filed Nov. 12, 1921 2 Sheets-Sheet2 .37 J8 I N 40 41 Zlwuantoz Paissieaoa. as, was,

enonenw. wnrnonn, an; or PHILADELPHIA, PENNSYLVANIA.

nnvron non rns rrne ELECTRIC orncurrs. c

Application filed November 12,1921. Serial no; 514,640, i

To all whom it may concern: I

Be it known that-I, GEORGE VVEIFORD, Jr.,a citizen of the United States,residing at Philadelphia, in the county'of Philadelphiaand State ofPennsylvania, have invented certain new and useful Improvements inDevices for Testing Electric Circuits, of which the following is'aspecification.

'.The object of this invention is to provide a strong and durableelectric-circuittesting device of novel, simple and efficient'construction for determining the condition of a circuit, whether liveor dead, or of a fuse,

whether good or blown, and for determin and aconnecting plug adapted tobe set in different positions on the casing to-setthe device in theproper conditlon for testing circuits of many different voltages,

Theinvention aims to provide a device having a testing lamp orlampsvvithin and protected by the casing which will burn at the samecandle power on any one of many voltages which-the device may he set toreceive, to avoidall danger incident to lamp explosions, and which willnot be m ured even under rough usage when in service.

The invention consists in the novel construction, combination andarrangement of partshereinaiter described and claimed.

I In the accompanying drawings, illustrating the invention, 1

Figure 1 is atop view of my improved testing device.

Figures 2, 3 and 4 are sections through the device on lines 2-2,j 3-5-3and 4-4, of Figs.

4, .2 and 3,- respectively.

Figure 5 is a diagrammaticview showing the electrical connections of thedevlce.

, Referring to thedrawings, the casing of the 'devic'ecomprises twoparallel cylindrical members (rand 6, a centrally-arranged,longitudinallyextending bar or member"? between the members 5 and 6, endheads 8 and 9 within and 'closiug'the ends of the cylindrical members 5and '6, respectively, a'central partition wall 10 within the member 6,

end plates 11,: and top and bottom plates 12 and 13. All these parts areformed of suitable strongand durable electrical insulating I materialsuch as fibre, hard i'rubber' 6r is the 'substance'well known asbalr'elite and all the parts are secured firmly together by suitablescrews, as shown in the dra'wl 's:

gtt l t z 5 The cylindrical member 5 encloses a chamberll containing asuitably constructed re f sistance coil 15. The member 6 encloses twochambers 16 and 17 separated. by-the partit on wall 10, and thesechambers contain two v incandescent testing lamps 18 and 19., The

lamps 18 and 19 extend through and are supported by sleeves or collars'20 and 21 which are fitted to the interior of the cylindrical.

member 6'; and the member 6 is) provided with slots or openings22'throughwhich the light from-the lamps 18 and 19 may be seen.

r "The central wall hr member 7 oil-the casing supports a plurality ofcontact'parts 23-, 245 '25, 26 and ;27,each comprising aplate'-s ecuredto" the wall 7 bya screw28 and a yielding arm extending. over the"screw, as

clearlyshown in Figs. 3and' lL Theconta-ct' plates 23,24, 25, 26 and27'are arranged di rectly beneath holes or openings 30,. 31, 32,- 33 and34, respectively, in the topplate'ory wall 1210f the-,casing.-

. Interposed between the walls 7 and is" a plate 35 of-electricalconductingmaterial having its longitudlnal edges resting on thecylindrical members 5 and 6 and held in place by screws 36. The plate 35is provided with screw-threadedholes 37,38, 39,40 and 41 which arearranged between andirr alinement'with thecontact' parts 23, 24l,-;25,26 and 27 and the'holesor openings 30, 31', 32, '33 and 34in the topwall 12 of the casing.

A plug42is provided having ahead 43 of insulating material"an d ascrew-threaded stem 44 of electricalconducting material adapted to beinserted into any on'e 'of the holes30, 31,. 32,33 andj34 andscrewed-into and through the holec in the plate/35') alined therewithand into engagement with the spring contact; armbeneath'the' same; andthus electrically connect the plate 35 and'the contact plate beneath thehole in-the wall 12 7 into which plug 421 inserted, f r a, purposel1ereinaft "Eirtendhg from the interior of th chain; hers 'lfiand 17 ofthe casing-to the exterior thereof through openings in the wall of thecasing member 6 are two terminal electrical conductors or lead 'wires 45and 46 which.

may be or, any suitable length. The inner portions of these lead wiresare connected to the parts of the device withi'rithe casing,

as will presently appear, and the outer or extends your l5 2 1t enterougg-h or inch i911} '8 hetweii the coil and its contact blade 49. Qhelead conduictoi- 4 16 is extends from the contact l port 23 :1 itsis/ends thr ugh or 1 t 1 9 oetwecn the Contact cart and t olade 50. Theend of the resistconnected to the wire 45 is conuted to the currentconducting e 5 t rou 7 it tot nlzne and the other coil is co; to theconihe contact are connected to the Y of the ends anccs from th \aiIQ assliowi no electric, merely for a 4. 4 of n the hole a t and down uponthe casing wall 12.

. 1 it will now be understoo that wiiei'l the plug 42 is set in con ththe part and thocontact blades s9 and 50 are applied to an electriccircuit, current will flow lcsd wire and its lamp 18, r the plate 35,the plug" 42, the not part the lead wire 46 and lar i 19, and will notflow through any .t oi 'the resistance coil 15. will also he understoodthat when the plug 42 is set in con'lsct with the part 2? the currentwill flow through the entire, resistance coil 15, and that when the plug42 is set in contact with any one of the parts 24, Q5 and 26, thecurrent will flow through only a nortion of the coil 15 whichisdetermincd hy the distance between the wire connecting the particularcontact part with the coil and the end of the coil connected to the leadwire 26. 7 r

The purpose of providing. a plurality of contact partsj connected to thecoil 15 at difierent distances from the end thereof connected to thepart23 and lead wire 46 is to cause the lamps 18 and 19 to burn at thesame candle power when the testing dev oi the resistance coil applied tocircuits of difierent wit-ages, and the plug 42 is set to include ot thecoil 15 or no part of the coil or s 'ic'icnt thereof :tor the voltage ofthe cirll the device is -pplied.

here n illustrated, provision is made L l oifierent voltages. These maybe creased or decreased as desired by increasl or decreasing the numberof points where the current may enter the coil 15 between the endsthereof. .eilso the different o'cs repre ented by the coil 15 hctweenleading theretroin and the 49 may he greatly varied by constructthe coilin accordance with the voltages ed, will be readily understood by sonsskilled in this art.

' herein illustrated, the device has a voltwhich includes alloonnncrcisl s, so that waen the plug 42 is erent holes or openings 30,31, there will be suificient resistdevice to cause the lamps and i m atthe same candle'nower on cirvolts,110 volts, 220 volts, ei l (3 volts,respectively, in accordthe {position of the plug 512. voltages areprinted or stamped unon the top wall or plate 12 of the casing adjacentto thehcles or openings 30, 3 02. respectively, as shown in i.

en it is desired to use the on circuit or" any one or" the live ,greshoroinbefore referred to, it is merenecessaiy to set the plus 42 in thehole in the casing corresponding with the volts c t circuit, andthereafter to apply the co blades 49 and 50 to the circuit in accordancewith the particular test being lTlilB, and in eccord-ance with the well,wn rules oi lamp testing, whereupon the rcseine or absence of lightwithin the 1. The combination of a casing, e resistance coil, anelectrical conducting, ar electrically connectec to one end or the coil,a ph'irality oi? terminal contact parts electrically connected to thecoil at different dis tances froin the' end thereof connector, to saidbar, means adjustable to different positions on said bar to electricallyconnect to any one 01" said parts, a terminal electrical. conductorleading from one end of said coil, and a terminal electrical conductorincluding atesting lump leading from the other end o-t said coil. I

2: The combination of a. casing, a plurslity of yielding contact parts,means to support the contact parts Within the casino; electricallyinsulated from each other, re-

llll) sistance coil Within thevcasing, an electrical conducting barhaving a plurality'of spaced openings therein corresponding in numberwith and positioned opposite tosaid contact parts and being supportedwithin the casing and electrically connected to one end of the coil,said contact parts being electrically connected to the coil at differentdistances from the end thereof connected to said bar, and a plug adaptedto be inserted into any one.

of said openings and when so inserted to electrically connect said barwith the contact part corresponding with the opening into which the plugis inserted, a terminal electrical conductor leading from one end i ofsaid coll, and a termlnal electrlcal conduc tor including a testing lampleading from the other end of said coil.

3. The combination of a casing, a plurality of yielding contact parts,means to support the contact parts within the casing electricallyinsulated from each other, a resistance COll within the caslng, anelectrical conducting bar having a plurality of spaced, screw-threadedopenings thereilr 'c-orrespondlng in number wlth and posttioned oppositeto said contact parts and I being supported within the casing andelectrically connected to one end of the'coil, said contact parts beingelectrically connected to the coil at difierent distances from the endthereof connected to said bar, and a screw-threaded plug adapted to bescrewed into any one of said openings to electrically connect said barwith the contact part corresponding with the opening receiving the pluga terminal electrical conductor leading from one end of said coil, and aterminal electrical conductor including a testing lamp leading from theother end of said coil.

i. The combination of a casing having a plurality of spaced openings'ina wall thereof, a resistance coil within the'casing a testing lampwithin the casing, a terminal electricalconductor connected to one end vof the coil and extendingthrough the casing to the exterior thereof, asecond terminal electrical conductor extending from the interior to theexterior ofvthe casing, and a connecting plug adapted to be insertedinto any one of said openings andprovided with means to electricallyconnect the last named conductor to the coil at different distances fromthe enclfthereof connected to the first named conductor, said distancesbeing. govported Within the casing between said wall and said member andconnected to oneend' of saidcoil and having a plurality ofopenings-therein in alinement with said contact parts and the openingsin said wall, said contact parts being electrically connected to thecoil at different distances from theend thereof connected to said bar, aconnecting plug adapted'to beinser'ted into any one of the openings in'said wall'pass through the alined'opening in said member and elecvtrically connect the member with the alined contactpart, a terminalelectrical conduct-or connected to one end of the coil and extendingthrough the casing to the exterior thereof; and a terminal electricalconductor connected to the other end of the coil and extending throughthe casing to the exterior thereof; said casing having an opening andthe lamp being included in one of the terminal electrical conductors; VI

In testimony whereof I aflix my signature hereto,

, p GEORGE wjwnironn'yf R.

therein through which the lamp may be seen i

